June, wo;.] KUSANO.— NUCLEUS OF SYNCHYT. PUERARIJE. 119 



magnification using the apochromatic 2.0 mm. objective of Zeiss 

 with compensating oculars. The results obtained up to the 

 present may be briefly stated as follows : 



1. The nucleus of the swarm-spore contains from two to 

 three small chromatic granules and a comparatively small, 

 somewhat compressed nucleolus lying on the inner surface of 

 the nuclear membrane. 



2. In the youngest fungus body infecting the host cell, the 

 nucleus becomes soon prominent in its size, accompanied by the 

 enlargement of the nucleolus while the chromatic and achromatic 

 substances are comparatively small in quantity. 



3. At somewhat advanced stage the chromatic globules of 

 various sizes increase in number, accompanying the vacuolation 

 of the enlarging nucleolus. The former collect into irregular 

 heaps encasing the nucleolus. They are probably derived from 

 the nucleolus. 



4. In the full grown nucleus we find numerous secondary 

 nucleoli passing out after the other from the primary nucleolus 

 and leaving large vacuoles inside the latter. They are connected 

 in links or scattered irregularly in the cavity of the nucleus. 

 It seems to the writer that they correspond to what Stevens 

 has given as the large " globules of chromatin " in 5. decipiens. 

 We see, however, in a well-differentiated preparation that they 

 are quite different from the usual chromatin in staining qualities. 



5. In both primary and secondary nucleoli, condensation of 

 chromatic substance which was previously existed uniformly in 

 them, now takes place. At first it arranges itself in the peri- 

 pheral portion of each nucleolus and then accumulate into 

 chromatic globules, whereas the interior of the nucleoli loses 

 the staining power towards hematoxylin and safranin. 



6. At the next stage the ground substance of the secondary 

 nucleoli begins to disintegrate and is transformed partly to the 

 linin or achromatic substance, by which the chromatic globules 

 are set free (see Steven's Fig. 5.) 



7. Gradual decrease of chromatic substances now follows, 



i) Bot. Gaz. XXXV. Plate XVII. Fig. 4. 



